Screw-propeller.



PATENTED AUG, 11, 11903.

n SHEETS-SHEET 1.

. G. PINKERT.`

SCREW PROPELLEE. APPLICATION FILED APR. 14, 1963..

N0 MODEL'.

isEBETs-smm.

PATENTED AUG-.(11, 1903. G. PINKERT.. SCREW PROPELLBR,

APPLICATION FILED APR. 14, 1903.

`No MODEL.

- for the fixinganges of the blades.

No. 735,905.l

UNITED STATES Patented August 11, 196s,

GRoRG P1NKERT,oF HAMBURG, GnRMAnvl SCREWPROPE`LLEFL SPECIFICATEQN forming' part of Letters Patent No. 735,905, dated August 1.1, 1903.

Application tiled April 14, 1903.

To a/ZZ whom t may concern.-

Be it known that I, GEORG PINEERT, a subject of the Emperor of Germany, residing at Hamburg, Germany, have invented certain new and useful Improvements in Screw-Propellers, of which the following is a specification.

In the constructions heretofore employed for securing the blades of a screw-propeller to the boss there is a disadvantage which is 'very prejudicial to the useful effect of the screw-namely, that the boss must have an angular form in order to offer a secure basis These xing-flanges also increase the size of the boss considerably and make the boss of the completed screw still more angular, while the screw studs and nuts serving to secure the fixing-flanges to the boss project beyond the anges themselves and produce foaming of the Water.

The present invention relates to improved means for securing the screw-blades to the screw-boss; and the Objectis to leave to the boss its round shape and to render unnecessary the blade-fixing flanges, as well as the screw studs and nuts heretofore employed. The improved means of securing also facilitates the changing of the blades and altering of their pitch. Furthermore, by the su ppression of the usual fixing-Bauges the employment of thin rolled or forged screw-blades of tough elastic material with sharp cutting edges is rendered possible, whereby the friction and certain other resistances of the screw-blades in the water and the consequent loss of useful effect are materially reduced.

In the accompanying two sheets of drawings are shown various methods of carryingl the invention into effect. V

Figure l shows a sectional elevation of a four-bladed propeller on the line C-D of Fig. 4 according to my invention; Fig. 2, a scctional elevation of same on the line A B of Fig. 3. Figs. 3 and 4. show, respectively, side and rear views of the propeller. Fig.v 5 is a diagrammatic view illustrating the adjustability of the screw-blades, and Fig. 6 shows a construction ofthe boss of the screw corre- 5o sponding to Fig. 3 in which a uniform adjustment of all the blades is effected by means of sain No. 152.572. (No man.) 4

special devices. Figs. 7 and 8 show the same method of securing the blades as that shown 1 in Figs. 1 and 2, but with the addition of a connecting-sleeve. Figs. 9`to 12 are sectional views of further modifications of the devices for securing the screw-blades. Figs. 13 to 16 show cross-sections of joints for the hollow spherical segments which serve to secure the blades in place. f 'The fundamental idea of the invention is that of holding the screw-blades by their bases on a spherical boss by means of hollow spherical segments adjustable on the said spherical boss', which latter is secured on the shaft, so that it cannot turn thereon, and the said spherical segments are pressed firmly onto the bases of the screw-blades and vonto the spherical boss by means of two spherically-shaped clamping devices corresponding in shape to the external spherical surfaces of the hollow spherical segments .by

tightening up a special screw-nut or by tightening up of the end nut on the propellershaft used for securing the entire screw-propeller on the shaft. be pinned at their bases into the spherical rlh-e screw-blades may j' boss or may take' onto pins formed on or fixed in the spherical boss itself, so as to be rotatable on their virtual axes passing through the center of the spherical boss to enable them to be adjusted so as to vary their pitch, if necessary, the hollow spherical segl ments being so placed between the blades that when moved in opposite directions they eect this desi red tu rning of the screw-blades. v The securing devices (shown in Figs. l to' 4) are constructed as follows: The boss of the screwjconsists of a spherical boss a, bored out conically, as usual, to tit onto the conical part of .the screw-shaft 'w and is prevented from,

turning thereon by means of keys in the usual way. 0n this boss are placed hollow spher ical segments l), with their inner spherical surfaces exactly fitting the outer sphericaly surface of the boss. segmentsl) as fixed by practical experiments is double that of the screw-blades'. The shape of these segments is the same in all and depends partly upon the cross-section of the screw-blades f. The hollow spherical segments b are held in place longitudinally of The number of these.

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the shaft fw by two dish-shaped clamping devices 7c k, which extend`as far over the lsegments b as' the screw-blades f will allow, whereby an intimate' contact of the inner surfaces of the clamping devices 7tla with the outer surfaces of the segments b is secured. The clamping devices k Zt are bored to suit the conical shape of the shaft w, and they may be prevented from rotating on the shaft by keys, like the boss a. A washer 'h takes the pressure of the screw-nut r, whereby the whole of the parts composing the boss are pressed firmly together, the front clamping device k thereof being pressed against the collar t' of the shaft w. likewise be prevented from turning on the shaft w by' means of keys. The screw-blades.

f are rototable on pins c of the spherical boss a perpendicularly to thelongitudinalaxis of the shaft w, the axial lines of such pins passing through the center of the spherical boss a. These pins cinay be fixed either in the spherical boss ct or in the bases of the screwblades j". The inner surfaces of the bases ofA the blades f correspond exactly to the shape of the spherical boss a and bear at all parts firmly against the latter. The bases of the blades f are provided with laterally-projecting fixing-flanges e, which are overlapped by the inclosing'hollow spherical segmentslb;

The process of putting together the parts composing the screw-propeller will bel easily understood from an inspection of Figs. l'to 4 and is as follows: First the front clamping device lo isv pushed onto the shaft w as far as the collar i and the spherical boss a is put on the shaft.l Thebladcs f are then,

placed with their bases against the spherical boss a. The hollow spherical segments b are next placed on-the bossa between the blades f. Then the rear clamping device k .and the washer h are pushed onto the shaft, and finally the whole is pressed firmly together by screwing up the nut fu. In screwing up the nutte care must be taken that the blades f take the-intended pitch.

the others must automatically take exactly the same pitch, because, on the one hand, by reason ofthe exactly opposite placing of each of the similarly-formed segments b, and, on

exactly similar angular position 0f all the` blades f is` secured and a separate adjust ment ot' each of the blades is therefore rendered unnecessary. v

As it is desirable in most cases to put thev screw-propeller together complete before placing it on the shaft fw, the further ar rangements shown in'FigsQ' to l2 have been devised to facilitate the carrying out of that.

object.

The construction shown in Figs. 7 and 8 The washer h may If, however, one` blade is made to take the required pitch, all i dilers only from that above described in thatV the front clamping device k `projects back# ward nearly to the washer h, so as to serve as a connecting-sleeve k'. i This sleeve It is bored out conically to tit the conical shaft, w and is prevented from turning on the latter by means of keys in the usual way. Exter nally the sleeve k is cylindrical, [and the spherical boss' a, segmentsb, screw-bladesf, and rear clam ping device la are pushed onto this cylindrical sleeve k.- The rear end` of the sleeve 7c' is furnished with a screw-thread, onto which is screwed the nut m, for which a recess is formed in the rear pressure-re ceiving surface of the clamping device k and by which nut the whole of the parts composing the boss device are pressed together. The annular remaining edge of the rear pressurereceiving surface of the clamping devicelc must project a little beyond the rear end ofy the sleeve la and of the nut m, screwed on the latter. by means of the Washer'h, on the clamping device k and acts as a lock-nut.

In the modification shown in Fig. 9 the hollow spherical segments b are cast on or fixed to one side ofthe base of the blade, and such a segment b may be regarded as an ex` tension of the flange e ofthe arrangement already described. The pivot-pin c may be cast in one piece with the base of each blade.

The device for fastening the blades shown.. w l x Then the shaft-nut v exerts pressure,

in Fig. l0 differs from those previously described in that the base of the bladef is nu k xcouj e e are not required.

In Figs. ll and l2 is shown another modiiication, lin which the xing-fianges a', made in one piece with the blades f, are formed as spherical segments, the outer surfaces of which complete the spherical boss u..` Fnrthermore, in this arrangement a connectingsleeve a2 forms a part of the spherical bossal and projects in both directions concentric with the axis of its bore to the requisite distance. This sleeve a2 is provided at both ends with screw-threads, onto `which the nuts m and n are screwed and effect the ressing together of the whole of the parts. .Ilach of the clamping devices k 7c has at its'outer pressure-receiving surface a recess for the reception of the nuts m or n. The annular pres.-

somewhat beyond the nuts m andn, so that the pressure of the shaft-nut v is received by them, and all parts .of the boss are pressed together bythe pressure of the said nut u.

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'sure-surfaces around these recesses project The nuts m and n should only serve for holding together the parts of the screw-propellers, the requisite pressure for securing the blades j' tothe boss being given chiefly orwholly by the much more powerful action of the shaftnut fv, whereby the latter serves at Sametime as a lock-nut. The connecting-sleeve a2 (shown in Fig. 1.1) may form a part of the spherical boss a in the construction shown in Figs. 9 and 10. In the arrangements shown in Figs. 9 to 12 the sleeves la' or a2 may be entirely omitted and the simpler fixing for the screw-blades shown in Figs. 1 to 4 be employed instead thereof.

The means for enabling the pitch of the screw-blades f to be altered are illustrated in Figs. 5 and 6i As already stated, the limiting-curves of the hollow spherical segments b are partly dependent upon the cross-sections of the screw-blades f at the points of contact between the latter andthe segments.' In the drawing Fig. 5 there are shown for the sake of clearness only two blade -sections f f', with the segments b b placed between them. These segments are connected together so as to form a kind of cap by a suitable joint s,

I which, as shown by way of examples in Figs.

13 to 16, may be constructed in various ways. The halves of this cap aromi/aged in opposite directions, as shown by thefaix'jifcuwsA -and y, by turning the blade f, so that tlebreadth of the divided cap lying between eachft'wo blades f' adapts itself exact-ly, to the varying distance apart of the blade-surfaces that are turned toward each other by the rotation of the blades, so that there is always intimate contact between the curved surfaces of the blades fand those of the segments or cap. In Fig. 5 the dotted lines indicate a movement of the segments b in the directions of the arrow a; and y; but it should be observed that the alteration of the pitch of the blades f is shown exaggerated. In practice it is only a question of altering the pitch of the screw to the extent of two or three degrees. The segments b b are so curved at the pointed ends, which are turned toward the shaft fw, that the said ends in case of a reverse movement come to bear against the shaft w. v

In the construction of the propeller-boss shown in Fig. 6 the clamping devices k k extend farther over the segments b and in between the blades f and are furnished with suitable recesses t, into which take the clawlike edgesof the blades. Itl with this construction an alteration of the pitch of the propeller-blades f be required, the shaft-nut v is first slackened.. Then thc clamping devices kl la are turned,hy means of suitable tools, in the direction of the arrows until the requiredalteration of the pitch of the blades f is effected,

' whereupon the whole boss system is tightened together again rmly by the nut lv. As by the engagement of the edges of the blades in the recesses t of the clamping devices la k all the blades f are uniformly turned together, they all take exactly the same pitch without the necessity of adjusting each blade separately.,

By turning the blades f ninety degrees and l.replacing-'fthe hollow spherical segments b with reversely-divided segmentsa right-handed screw canbe altered to a left-handed, and vice versa.

What I claim is- 1. In screw-propellers, the combination vof the conical shaft, screw-blades, ixing-iangcs on said blades, a spherical boss secured on said shaft, a plurality of spherical segments with recesses adapted to receive the said bladeflanges, clamping devices partly overlapping the said segments, and means for holding the various parts together, substantially as set forth v 2. In screw-propellers, the combination of the conical shaft, screw-blades, xing-iianges on said blades, a spherical boss secured on said shaft, a plurality of spherical segments with recesses adapted to receive the said blade-flanges, clamping devices with recesses adapted to receive the edges of the said blades and partly overlapping said segments, and

means for holding the various parts together, substantially as set forth.

3. In screw-propellers, the combination of the conical shaft, screw-blades, pivot-pins on said blades, fixing-flanges on said blades, a sphericalvboss secured on said shaft and adapted to receive the said pivot-pins, a plurality of spherical segments with recesses adapted to receive the said blade-anges, clamping devices partly overlapping the said segments, and means for holding the various parts together, substantially as set forth.

4. In screW-propellers, the combination ofthe conical shaft, screw-blades, one-sided long tianges on said blades of spherical segmental shape, short fixing-flanges on the other side of the blades, extensions on said blades below the said ilanges, a plurality of spherical segments with recesses adapted to receive the said blade-flanges, a spherical boss secured on said shaft and adapted to receive the said blade extensions, clamping devices partly overlapping said segments, and means for holding the'various parts together, substantially as set forth. l

. 5. In screw-propellers, the combination of the conical shaft, a spherical boss with circumferential recesses on said shaft, screwblades, a spherical segmental base on `said blades adapted to take in to the recesses of said boss, a plurality of spherical rabbeted segments adapted to fit over said blade-bases, and clamping means for holding the various parts together, substantially as set forth.

6. In screw-propellers, the combination of the conical shaft, a sleeve keyed onsaid shaft, a spherical boss riding on said sleeve and secured against rotation thereon, screw-blades,

fixing-flanges on said blades,fa plurality of I In testimony that I claim the foregoing'as spherical segments with recesses adapted to I `my invention I-have signed my name in presreceive the said blade-flanges, clamping deence of two subscribing witnesses.

vices partly overlapping said segments, indel GEORG PINKERT. pendent means for tightening' the said clamp- Witnesses:

ing devices, and means for holding the varil LOUIS SDECUM,

ons parts together, substantially as set forth. CARL FRANCK'. 

